Electrical switching devices, especially those employed in the control of electrical circuits in domestic appliances, are often operated by changes in temperature, pressure, liquid levels, electric power, or the like and utilize various different power elements, such as bi-metals, bellows, floats, and magnetic armatures or the like for instance. Such power elements must be of sufficient size to properly operate the contacts for switching the electrical load of relatively high currents for a large number of trouble free cycles of operation, for instance for more than 100,000 cycles of load life in one particular application. It is highly desirable to keep the size of the unit small and compact, low in cost, yet the components of the unit must be sufficiently rugged to operate properly over long periods of time without failure. Additionally, it is desirable to maintain the differential in the working substance, such as temperature and pressure changes or the like for instance, within small limits for best control. It is also desirable that the switching devices be versatile in nature, essentially no contact bounce which could otherwise produce arcing and potential contact welding, and enough contact wipe, for instance 0.010 inch, so that wear will not be detrimental to the operating characteristics of the device. It is additionally desirable to be able to accomplish the foregoing without the need to totally redesign existing devices. These advantageous features and desirable attributes should be obtained in an economical yet highly effective manner.
Accordingly, it is an object of the present invention to provide an improved electrical switching device and a method of operating which provide the more important desirable features identified above.
It is another object of the present invention to provide an improved electrical switching system which is sturdily and economically built, relatively compact, and capable of trouble-free operation over a long period of time, yet which has components adapted to furnish amplified contact forces.